Progressive Dilated Cardiomyopathy in a 24-Year-Old Man: A Rare Manifestation of Propionic Acidemia

Adult onset propionic acidemia (PA) is exceedingly rare, particularly when manifesting as dilated cardiomyopathy.

A previously healthy 24-year-old man presented with cardiac dilatation and acute progressive heart failure. His condition was refractory to guideline-directed medical therapy, deteriorating to cardiogenic shock within 6 weeks. Plasma acylcarnitine profile revealed elevated propionylcarnitine and an increased propionylcarnitine-to-acetylcarnitine ratio. Urinary organic acid analysis showed elevated methylcitric acid. Whole-exome sequencing identified a homozygous mutation in the PCCA gene. A diagnosis of PA presenting as metabolic cardiomyopathy was established. Cardiac function and hemodynamics improved with targeted metabolic treatment combined with guideline-directed medical therapy.

Adult onset, metabolic cardiomyopathy because of PA is prone to being overlooked or misdiagnosed as refractory idiopathic dilated cardiomyopathy, potentially leading to premature escalation to advanced heart failure therapies. Early etiologic recognition and targeted metabolic treatment are crucial in the management of such cases.

Metabolic and genetic screening is recommended for patients with idiopathic dilated cardiomyopathy, particularly in younger individuals. Early diagnosis and targeted intervention may preclude or delay the progression to left ventricular assist device implantation or heart transplantation in patients with dilated cardiomyopathy secondary to PA.